HbA1c (Average Blood Glucose)

HbA1c measures the proportion of haemoglobin in your red blood cells that has glucose attached to it. Because red blood cells live for around three months, the value reflects blood glucose across that whole period rather than at the moment of testing. That makes HbA1c less sensitive to what you ate or how you slept the day before. No fasting is required.

Why Test HbA1c?

A normal fasting glucose does not rule out blood glucose having been raised over a longer period, and HbA1c captures that slower change. It is used to detect pre-diabetes and diabetes, and to follow treatment in people who already have diabetes. It is particularly relevant if diabetes runs in your family, if you carry extra weight, or if you want to see the effect of changes to diet and exercise.

What Do High HbA1c Levels Mean?

A raised HbA1c means blood glucose has averaged higher than normal. In Sweden, 42–47 mmol/mol indicates increased risk (pre-diabetes), and 48 mmol/mol or above on two occasions indicates diabetes. Common causes are insulin resistance, excess weight, low physical activity and certain medicines such as corticosteroids. Long-term raised blood glucose increases the risk of disease affecting the heart, kidneys, eyes and nerves, which is why it is worth detecting early.

What Do Low HbA1c Levels Mean?

A low HbA1c usually means blood glucose has been well controlled. Unusually low values can, however, reflect conditions that shorten the lifespan of red blood cells, such as haemolytic anaemia, bleeding or a recent blood transfusion. In iron deficiency and in kidney or liver disease the value can be misleading. An unexpectedly low result should be interpreted alongside a full blood count.

Symptoms to Watch For

Increased thirst and passing large amounts of urine
Persistent fatigue and lack of energy
Increased appetite and unintended weight change
Blurred vision
Wounds that heal slowly
Tingling or numbness in hands and feet
Recurrent infections

Who Should Get Tested?

People with type 1 or type 2 diabetes in the family
People carrying extra weight, particularly around the waist
People who move little or have high blood pressure
People diagnosed with pre-diabetes or insulin resistance
People with diabetes following their treatment
People who have had gestational diabetes

How to Prepare for Your Test

No fasting is required for HbA1c. If it is taken at the same time as fasting glucose or blood lipids, fast for at least ten hours. Bring valid ID to your appointment.

Order Your Blood Test

Test your HbA1c levels with an accredited Swedish laboratory. Results within days, reviewed by Wellth.

HbA1c (Glycated Haemoglobin) →

Frequently Asked Questions

What is a normal HbA1c?

A value below 42 mmol/mol is normal. Between 42 and 47 mmol/mol indicates an increased risk of developing diabetes. At 48 mmol/mol or above, confirmed by a repeat test, diabetes is diagnosed. Your result states the laboratory's reference interval.

How often should I test my HbA1c?

In diabetes, HbA1c is usually checked every three to six months according to your doctor's plan. If you have risk factors but no diagnosis, once a year is usually enough.

Can HbA1c be lowered without medication?

In pre-diabetes, regular physical activity, fewer fast-acting carbohydrates and less added sugar, weight loss and better sleep can lower the value over time. In diabetes, your doctor decides whether medication is needed. Never change prescribed treatment on your own.

Why is HbA1c more stable than a single blood glucose reading?

A blood glucose value shows the moment of testing and is affected by meals, sleep and stress. HbA1c reflects an average across two to three months and therefore varies less from day to day.

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Wellth Team

Wellth

Our content is written and reviewed by Wellth, and fact-checked against peer-reviewed research and current Swedish clinical guidelines.

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Medical Disclaimer

The information on this page is provided for informational purposes only and does not constitute professional medical advice, diagnosis, or treatment. Wellth provides health information and testing services but is not a substitute for clinical care. Always consult a qualified healthcare provider if you have questions about a medical condition. If you are experiencing severe or urgent symptoms, contact your doctor or call 1177 Vårdguiden. Blood test results should be interpreted by a qualified healthcare professional in the context of your complete medical history.